Keystart switches are used in operating machines of all types, such as automobiles, motorcycles, snowmobiles, trucks, and farm, construction and mining equipment. Many of these operating machines do not have an enclosed cab for protecting the operator and control panel from the environment. Instead, the operator and control panel are exposed to the environment. One component of the control panel that is particularly sensitive to environmental conditions is the keyswitch.
Conventional keyswitches typically have a lock cylinder and a housing. Upon insertion of an appropriate key, the lock cylinder is rotated, causing an electrical contact on the lock cylinder to make contact with an electrical contact on the housing. This closes a loop, forming a circuit that activates a function. Typical functions activated by a keyswitch in an operating machine are providing power to the accessories (such as lights, radio, power steering, etc.), or engaging the starter motor to crank the engine.
Environmental conditions, especially moisture, can cause abnormal operation of conventional keyswitches. Rain can penetrate the keyswitch and short-circuit the electrical contacts, causing the keyswitch to malfunction. A similar short-circuiting can also occur by other physical contaminants, such as some types of dust for example, entering the keyswitch.
One attempted solution to this problem is the use of seals around the exposed portions of the keyswitches. However, moisture and other contaminants can still enter the keyswitch via the keyhole. Further, the seals dry out and crack over time, allowing moisture and contaminants to enter through the cracks.